Phone Defense Call Blocker One (1) year of warranty. 30-day return policy. NOTE: The caller ID is NOT a part of this product, this product requires a caller ID service Line powered - It uses the power from your phone line, requires no batteries or power adapters. Compatible with FSK/DTMF, PSTN (copper based) house landlines, and VOIP services (Vonage, MagicJack, and others). Also Verizon FIOS, and cable companies (Comcast, CableOne, TimeWarner, and others). Large Capacity -- Block up to 1,500 telephone numbers. Also ten (10) area codes and/or prefixes (3-5 digits in length) Easy to Setup & Use - Simply press a button to permanently block unwanted calls